The Northern Rif (Northern Morocco, Northwestern Africa) was characterised in the late Pleistocene and the Holocene by mammal assemblages, which included species with different biogeographic origins. Saharian, Saharo-Mediterranean, Sahelian species as well as some forms adapted to the Mediterranean climatic regime have been recorded. The fossil mammal assemblages recovered from two new localities in karstic infills (Chrafate and Ez Zarka) correspond well with this palaeobiogeographic setting and suggest that this region was a crossroad of palaeoartic and palaeotropical species. The variety observed in the fossil mammal assemblages and in the present mammal fauna resulted from a long period of aridity, which coincided with the late Pleistocene post-glacial stage and was followed by a Holocene humid phase. This palaeoclimatic change resulted from the equator ward shift of the high-pressure cell belt, which allowed the southward shift of less arid Mediterranean climatic zones.